import React from 'react';
import ReactDOM from 'react-dom';
import './index.css';

export interface SquareProp {
  value: null | 'O' | 'X';
  onClick: Function;
}
// export interface SquareState {
//   value: string | null;
// }
class Square extends React.Component<SquareProp> {

  render() {
    return (
      <button className="square"
        onClick={() => this.props.onClick()}>
        {this.props.value}
      </button>
    );
  }
}


export interface BState {
  squares: Array<null | 'O' | 'X'>;
  next: Boolean
}
export interface BProp {
  squares: Array<null | 'O' | 'X'>;
  handleClick: Function
}
class Board extends React.Component<BProp, BState> {

  renderSquare(i: number) {
    return <Square value={this.props.squares[i]}
      onClick={() => this.props.handleClick(i)}
    />;
  }

  render() {
    return (
      <div>
        <div className="board-row">
          {this.renderSquare(0)}
          {this.renderSquare(1)}
          {this.renderSquare(2)}
        </div>
        <div className="board-row">
          {this.renderSquare(3)}
          {this.renderSquare(4)}
          {this.renderSquare(5)}
        </div>
        <div className="board-row">
          {this.renderSquare(6)}
          {this.renderSquare(7)}
          {this.renderSquare(8)}
        </div>
      </div>
    );
  }
}

export interface GState {
  history: Array<any>,
  next: Boolean,
  stepNumber:number
}
class Game extends React.Component<{}, GState> {
  constructor(props: {}) {
    super(props)
    this.state = {
      history: [{
        squares: Array(9).fill(null),
      }],
      next: true,
      stepNumber:0
    }
  }
  handleClick(i: number) {
    const history = this.state.history.slice(0,this.state.stepNumber+1);
    const current = history[history.length - 1];
    const squares = current.squares.slice();
    if (calWinner(squares) || squares[i]) {
      return;
    }
    squares[i] = this.state.next ? 'X' : 'O'
    this.setState({
      history: history.concat([{
        squares: squares,
      }]),
      next: !this.state.next,
      stepNumber:history.length
    })
  }
  jumpTo(step:number){
    this.setState({
      stepNumber: step,
      next: (step % 2) === 0,
    });
  }
  render() {
    const history = this.state.history;
    const current = history[this.state.stepNumber];
    const winner = calWinner(current.squares);
    const moves = history.map((i, step) => {
      const desc = step ? `Go to move # ${step}` : `Go to start`
      return (
        <li key={step}>
          <button onClick={() => this.jumpTo(step)}>{desc}</button>
        </li>
      )
    })
    let status: String
    if (winner) {
      status = `winner is ${winner}`
    } else {
      status = `Next player:  ${(this.state.next ? 'X' : 'O')}`;
    }
    return (
      <div className="game">
        <div className="game-board">
          <Board
            squares={current.squares}
            handleClick={(i: number) => this.handleClick(i)}
          />
        </div>
        <div className="game-info">
          <div>{status}</div>
          <ol>{moves}</ol>
        </div>
      </div>
    );
  }
}

// ========================================
const render = () => {
  ReactDOM.render(
    <Game />,
    document.getElementById('root')
  );
}
render()

function calWinner<T>(squares: Array<T>) {
  const lines = [
    [0, 1, 2],
    [3, 4, 5],
    [6, 7, 8],
    [0, 3, 6],
    [1, 4, 7],
    [2, 5, 8],
    [0, 4, 8],
    [2, 4, 6],
  ];
  for (let i = 0; i < lines.length; i++) {
    const [a, b, c] = lines[i];
    if (squares[a] && squares[a] === squares[b] && squares[a] === squares[c]) {
      return squares[a];
    }
  }
  return null;
}